Hydraulic pump and cooler unit

ABSTRACT

An arrangement of a hydraulic pump and cooler unit for a hydrostatic drive mechanism, the unit comprises pump means, blower means, duct means, and heat exchanger means. The pump means and blower means are mounted on a single shaft so that they are coaxial and have common drive means. The heat exchanger means is located within the duct means, and both of said means are located directly above the blower means. The unit may include a reservoir means arranged side-by-side with the duct means and above the pump means. Said reservoir means may also include filtering means therein.

1451 Apr. 30, 1974 United States Patent 119] Mott, Jr. et a1.

415/178 Goettl................................ 415/98 [54] HYDRAULIC PUMP AND COOLER UNIT 1,037,659 9/1912 Rembert [75] Inventors: Carl W. Mott, Jr., LaGrange; Tmmy Middlesworth, Hinsdale, 2:30l:857 11/1942 Criqui........... both 0f 2,694,980 11/1954 Lauck et a1...

Primary Examiner-Henry F. Raduazo Attorney, Agent, or Firm-Hibben, Noyes & Bicknell ABSTRACT An arrangement of a hydraulic pump and cooler unit for a hydrostatic drive mechanism, the unit comprises v pump means, blower means, duct means, and heat exchanger means. The pump means and blower means are mounted on a single shaft so that they are coaxial and have common drive means. The heat exchanger means is located within the duct means, and both of said means are located directly above the blower means. The unit may include a reservoir means arranged side-by-side with the duct means and above the pump means. Said reservoir means may also include filtering means therein.

4 Claims, 5 Drawing Figures Assignee: Mott Corporation, LaGrange, Ill.

[22] Filed: Dec. 15, 1972 [21] App]. No.1 315,360

Related US. Application Data [62] Division of Ser. No. 111,954, Feb. 2, 1971 Pat. No.

[52] U.S. 415/121 G, 415/175, 415/178, 415/198, 55/400 [51] Int. F01d 15/08, FOld 15/10 [58] Field of Search 415/206, 98, 178, 175, 415/121 G, 121, 198; 165/96, 39,122; 56/128; 55/400, 406

[56] References Cited UNITED STATES PATENTS 1,832,619 11/1931 Cook 415/121 G 3,183,899 5/1965 55/400 III/1110111,

PATENTED APR 3 0 I914 SHEET 2 [IF 3 PATENTEDAPR30 19 38071893 SHEET 3 OF 3 HYDRAULIC PUMP AND COOLER UNIT This is a division of application, Ser. No. 111,954, filed Feb. 2, 1971 now US. Pat. No. 3,751,191.

This invention relates to a hydrostatic drive mechanism having a compact hydraulic pump and cooler unit.

Heretofore, it has been known to use a hydrostatic drive mechanism to operate various types of equipment. Such a mechanism usually includes a hydraulic pump for supplying pressure fluid for driving a hydraulic motor. Frequently, because of the large amount of heat transferred to the hydraulic fluid, cooling means, usually in the form of a fan and radiator, are also provided for cooling the hydraulic fluid. Attempts have been made to achieve a compact assembly of these components, but such attempts have been only partially successful.

The present invention eliminates the foregoing disadvantages by providing a hydrostatic drive mechanism having a hydraulic pump and cooler unit with compactly arranged components. Such unit comprises hydraulic pump means and cooler means, and the cooler means further comprises duct means having heat exchanger means therein, and blower means for disipating heat from the fluid. The hydraulic pump means and blower means are coaxially arranged and mounted on a single shaft, and drive means is provided for simultaneously driving the pump means and blower means. In addition, reservoir means having filter means therein, may be connected to the hydraulic pump means and heat exchanger means. The reservoir means and duct means are located side-by-side and may also be adjacent the coaxially arranged hydraulic pump means, drive means and blower means. Thus, the duct means extends transversely from the axis of the pump means and blower means.

Accordingly, it is the primary object of the present invention to provide a hydrostatic drive mechanism having a compact hydraulic pump and cooler unit.

Another important object of the present invention is to provide a hydrostatic drive mechanism of the foregoing character suitable for being mounted on a vehicle for driving various types of equipment carried by the vehicle.

Still another object of the present invention is to provide a hydraulic pump and cooler unit having pump means and blower means coaxially arranged and having a common drive means, reservoir means attached to said pump means, and duct means in side-by-side relation with said reservoir means and having a heat exchanger therein.

DESCRIPTION OF THE INVENTION These and other objects of the present invention will become apparent from the following description and accompanying figures of the drawings in which:

FIG. 1 is a perspective view of a tractor equipped with three mowers, two of which are driven by two hydrostatic drive mechanisms each utilizing a hydraulic pump and cooler unit embodying the features of the present invention,

FIG. 2 is an enlarged vertical sectional view of one of the hydraulic pump and cooler units shown in FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2; and

FIG. 5 is a reduced, top plan view of the unit shown in FIG. 2. v

In FIG. 1 a vehicle or tractor .is illustrated, to which are secured a rear mower l2 and two side mowers 14. The rear mower 12 is, in this instance, mechanically driven from the rear power take-off of the tractor 10. The side mowers 14'are pivotally mounted on the outer ends of a pair of frames 13, the inner ends of the frames 13 also being pivotally connected to. the sides of the tractor 10. Thus, the side mowers 14 can be moved, upwardly or downwardly, from their illustrated horizontal position, and can be pivoted. Such movements may be effected by conventional hydraulic cylinders (not shown) which receive hydraulic fluid under pressure from the hydraulic system of the tractor under the control of a multisection control valve 15. The mowers l2 and 14 have rotatable mower shafts 17 to which cutting elements 19 are'secured.

For convenience of installation, reduction in size, and increased operating efficiency, a separate hydrostatic drive mechanism embodying the features of the present invention, is utilized to drive each side mower 14. It will be understood that the hydrostatic mechanism to be hereinafter described could be used to drive other types of associated devices while located either on or off a vehicle. The provision of a separatehydrostatic drive mechanism for each associated device to be driven results in smaller, more easily handled components, and eliminates the pressure losses due to division of the fluid to drive two or more devices.

Each hydrostatic drive mechanism, in this instance, comprises a hydraulic motor 16 secured to one of the mowers l4 and driving the shaft 17 thereof, and a hydraulic pump and cooler unit 18. The motor 16 and unit 18 are connected together by conduit means in the form of flexible hoses 20 and 22; I

The two units 18 are preferably mounted on the respective sides of the tractor 10 and at one end thereof, preferably the front end. The units may thus be driven by a power take-off shaft at the front of the tractor. The units may be selectively connected to or disconnected from the power take-off shaft by manual controls 24.

As shown in FIG. 2, eachhydraulic pump and cooler unit 18 comprises pump means, such as a hydraulic pump 28, and cooler means indicated generally at 30. The cooler means includes a blower means 32, and a heat exchanger means 34 mounted within duct means 36. In this instance, reservoir means 38 having filtering means 40 therein, is also provided. The components are arranged with the pump means 28 coaxial with the blower means 32, the duct means 36 having the heat exchanger means 34 therein adjacent the blower means 32, and the reservoir means 38 in side-by-side relation with the duct means and adjacent the pump means 28.

The hydraulic pump 28 is conventional and has an outer housing 42, a fluid inlet pipe 44,11 fluid outlet pipe 46, and a shaft 48 rotatably mounted in the housing 42 and extending from one end thereof. When driven, the pump 28 draws hydraulic fluid from the reservoir 38 and supplies hydraulic fluid under pressure to the motor 16.

Drive means is secured to the shaft 48 and, in this instance, comprises a pulley 50 having an inner or hub portion 52 keyed to the shaft 48, and an outer portion 54 secured to the hub portion 52 as by bolts 56. The

,pulley 50, in the present instance, is driven by two V- belts 58 which extend around another pulley 60 (FIG. 1) mounted on the front power take-off shaft of the tractor 10. Since the blower 32 and pump 28 are connected to a single shaft 48, both may utilize the same drive means, i.e., the pulley 50.

The blower means 32, preferably comprises a squirrel cage rotor 62, and an enclosing housing 80. The rotor 62 includes a rear disk or plate 64 secured to the hub portion 52 of the pulley 50 by the bolts 56. An adapter 66 is located between the plate 64 and hub portion 52 so that the pulley 50 clears the rotor 62. The rear plate 64 is piloted on a portion 68 of the adapter 66 which serves to align the rotor 62 with the bore in the hub 52. Blades 70 are carried by the rear plate 64 and an annular front disk 72 forming part of the rotor. The axial center opening 73 of the front disk 72 forms the blower inlet and is covered by a screen 74 held in place on the rotor 62 by screws 76 and an outer annular disk 78. The screen 74 thus rotates with the rotor.

The rotor 62 rotates in the blower housing 80 which,

except for an opening 82 in its rear wall, an opening 84 in its front wall, and a blower outlet or opening 86 at its top and connected to the heat exchanger 34, is completely closed. The housing 80 has a flange 88 surrounding the opening 86 and is secured to the lower end of the duct 36 surrounding the heat exchanger. The front opening 84 and, in this instance, the rear opening 82, are larger than the diameter of the rotor 62 so that some of the air delivered by the rotor bleeds out through the annular clearances between the housing 80 and the rotor 62, constituting portions of the openings 82 and 84. This air bleed insures that all air entering the blower enters through the screen 74 covering the blower inlet. The air bleed thus prevents debris or other material from entering the blower or from accumulating on the portion of the unit adjacent the blower. Debris and other materials are also centrifugally prevented from accumulating on the screen 74. v

The heat exchanger 34 comprises two headers 90 and 92 connected by a plurality of transverse tubes 94 having thin heat transfer fins 96 secured thereto. The header 90 has an inlet 98, and the header 92 has an out let 100. The heat exchanger 34 is mounted in the duct 36 provided by a bottom wall 102, side walls 104, 106, 108, and a side wall 110 which also forms part of the reservoir 38, the top of the duct 36 being open. An opening 112 in the lower wall 102 aligns with the opening 86 in the blower housing 80 and permits passage of air from the blower 32 through the duct 36 to the heat exchanger 34.

The reservoir 38 is in side-by-side relation with the duct 36 and is also directly above the pump means 28. The reservoir 38 comprises the wall 110 which is common to the duct 36, side walls 128, 130 and 132, a bottom wall 134, and a top wall 136. The reservoir 38 is adapted to be filled with hydraulic fluid to a surface or level indicated by the broken line 109 in FIG. 2.

Fluid conducting structure is provided to supply hydraulic fluid to the heat exchanger 34 and to transmit the fluid from the heat exchanger to the reservoir. To this end the one means, i.e., the heat exchanger 34 is interposed in the fluid conducting structure. The fluid conducting structure includes an inlet connection 137 which at one end is connected to the hose 22, an inletpipe 138 which extends into the reservoir through an opening 139 (FIG. 4) in the reservoir wall 128, a pipe 140 extending into the duct 36 through an opening 141 (FIG. 3) in the common wall 110, and a hose 142 ex tending from the pipe 140 to the inlet 98 of the heat exchanger 34. A portion of the fluid flow is bypassed to the reservoir 38 through several openings 143 (FIG. 4) provided in the pipe 138 which is upstream of the heat exchanger. The remainder of the flow through the pipe 138 continues on to the heat exchanger 34. The bypass openings 143 are oriented in the pipe 138 so as to direct hydraulic fluid away from the hydraulic fluid level 109 in the reservoir 38, so that aeration of the fluid in the reservoir is minimized.

For flow from the heat exchanger 34 to the reservoir 38, the fluid conducting structure includes a hose 144 extending from the outlet 100 of the heat exchanger 34, a pipe 145 located in a second opening 146 (FIG. 3) in the common wall 110, and a transfer pipe 147. The transfer pipe 147 extends-through asecond opening 148 (FIG. 4) in the reservoir wall 128, and the end of the pipe 147 is closed by .a pipe cap 149 which may be fitted with a gauge, such as a temperature gauge 150. The pipe 147. has openings 151 within the reser-v voir downstream of the heat exchanger which are also oriented so that hydraulic fluid discharging through these openings is directed away from the upper surface 109 of the hydraulic fluid in the reservoir to likewise minimize aeration. All of the fluid flowing through the heat exchanger is discharged into the reservoir through the openings 151.

The pump inlet pipe 44 extends from the pump 28 through an opening l52'in the lower wall 134 of the reservoir 38 and is threaded into the lower end of a larger diameter pipe 154 positioned within the reservoir. The lower wall 134 of the reservoir 38 is clamped between the end of the pipe 154 and an annular boss 156 secured to the inlet pipe 44, as by welding, to retain and support the reservoir 38 above the pump 28. An O-ring 158 is provided in a groove in the boss 156 to form a seal. In this instance, a removable cover 160 has been provided in the top wall 136 of the reservoir. The cover 160 has a groove and O-ring 162 on its outer edge to seal the cover 160 to the wall 136. A removable filler plug 164 having a vent opening 166 therein, is threaded into the cover 160. The cover 160 is held in place by a single center bolt 168 which engages a threaded member 170 welded to the upper end of the pipe 154, the member 170 closing the upper end of the pipe 154. The cover 160permits replacement of the filter means 40, as hereinafter described.

The filter means 40 is contained within the reservoir 38, is placed directly above and connected to the pump 28 through the pipe 154 and the inlet pipe 44, and comprises a conventional cylindrical filter element 172 having a center passage 174. The filter element 172 is held in place by a spring 176 which abuts the cover 160 and the element, and is centered by the pipe 154. The

spring 176 is positioned by a tube 178 secured to the cover 160. The ends of the filter element 172 are sealed by engagement with seal washers 182. Openings 184 in the pipe 154 permit fluid to flow from the reservoir-38 through the filter element 172 to the pump 28.

In operation of the hydraulic pump and cooler unit, the drive means i.e., the pulley 50 is driven by a tractor power take off shaft, and in turn drives the pump 28 and blower rotor 62. Hydraulic fluid is pumped from the reservoir 38 by the pump 28 through the outlet pipe 46, and the hose 20, to the hydraulic motor 16, which drives the mower 14. The hydraulic fluid returns from the motor 16 through the hose 22 and the pipe 138. A portion of this fluid flows directly into the reservoir 38 through the bypass openings 143 in the pipe 138 to be recirculated by the pump. The remainder of the fluid flows through the pipe 138 and enters the heat exchanger 34, is cooled therein, and is returned to the reservoir through the hose 144 and the holes 151 in the transfer pipe 147. Fluid from the reservoir 38 is then drawn through the filter element 172 and the pipe 154 and the inlet pipe 44 by the pump 28 to again be supplied to the motor 16.

The blower rotor 62 draws air through the rotating screen 74 which is flat and which lies in a plane spaced outwardly of the plane of the front wall of the housing 80, and the rotation of the screen 74 centrifugally throws any debris radially outward. A small portion of this air is bled off through the clearances between the rotor 62 and the openings 82 and 84 of the blower housing 80 and thus blows the debris away from the housing that has been centrifugally thrown radially outward. Most of the air, however, passes through the duct 36 and then passes through the heat exchanger 34 to the hydraulic fluid.

It is apparent from the foregoing that a hydrostatic drive mechanism having a compact hydraulic pump and cooler unit has been provided, wherein a hydraulic pump means and blower means are in coaxial arrangement, duct means having a heat exchanger means therein is located to extend transversely from the blower means. Reservoir means may be located in sideby-side relation with said duct means and adjacent said pump means, and filter means may be located within said reservoir means.

We claim:

1. In a hydraulic pump and cooler unit including pump means and blower means, said blower means including a housing having opposite walls and an opening in one of said walls, said housing also having an air outlet therein, a rotor in said housing extending into said wall opening, said rotor having an axial opening providing an air inlet for said blower means, and a screen carried by said rotor and extending across the inlet opening therein, said wall opening and said rotor being sized to provide a clearance therebetween, and the pressure of the air in said housing outside of said rotor causing air to flow from said housing through said clearance and thereby causing substantially all of the intake air to be drawn through said screen.

2. The combination of claim 1, wherein an opening is provided in the other of said housing walls, said rotor extends into said other wall opening, and said other wall opening and said rotor are sized to provide a clearance therebetween, said pressure of the air in said housing causing air to flow through said last mentioned clearance.

3. The combination of claim 1, wherein the centrifugal force imparted to debris contacting said rotating screen coacts with the flow of air from said housing through said clearance to throw such debris away from said housing. I

4. In a hydraulic pump and cooler unit including pump means and blower means, said blower means including a housing having opposite walls and an opening in each of said walls, said housing also having an air outlet, a rotor in said housing extending into said wall openings, said rotor having an axial opening providing an air inlet for said blower means, and a screen carried by and rotatable with said rotor and extending across said inlet, said screen being flat and lying in a plane spaced outwardly of the plane of the end wall of said housing adjacent said rotor inlet, whereby said screen is operable to throw debris away from said inlet and away from said housing due to the centrifugal force imparted to such debris by the rotation of said screen. 

1. In a hydraulic pump and cooler unit including pump means and blower means, said blower means including a housing having opposite walls and an opening in one of said walls, said housing also having an air outlet therein, a rotor in said housing extending into said wall opening, said rotor having an axial opening providing an air inlet for said blower means, and a screen carried by said rotor and extending across the inlet opening therein, said wall opening and said rotor being sized to provide a clearance therebetween, and the pressure of the air in said housing outside of said rotor causing air to flow from said housing through said clearance and thereby causing substantially all of the intake air to be drawn through said screen.
 2. The combination of claim 1, wherein an opening is provided in the other of said housing walls, said rotor extends into said other wall opening, and said other wall opening and said rotor are sized to provide a clearance therebetween, said pressure of the air in said housing causing air to flow through said last mentioned clearance.
 3. The combination of claim 1, wherein the centrifugal force imparted to debris contacting said rotating screen coacts with the flow of air from said housing through said clearance to throw such debris away from said housing.
 4. In a hydraulic pump and cooler unit including pump means and blower means, said blower means including a housing having opposite walls and an opening in each of said walls, said housing also having an air outlet, a rotor in said housing extending into said wall openings, said rotor having an axial opening providing an air inlet for said blower means, and a screen carried by and rotatable with said rotor and extending across said inlet, said screen being flat and lying in a plane spaced outwardly of the plane of the end wall of said housing adjacent said rotor inlet, whereby said screen is operable to throw debris away from said inlet and away from said housing due to the centrifugal force imparted to such debris by the rotation of said screen. 